(Persia Digest) - The Trump administration on Wednesday imposed sanctions on an elaborate shipping network that Iran uses to sell oil, and unveiled a $15 million reward to anyone with information that disrupts the scheme, stepping up its effort to exert pressure on the Iranian economy.

The New York Times reports that sanctions were the latest in a flurry of actions taken by the United States in recent days to further isolate Iran in hopes that it will return to the bargaining table to renegotiate an international agreement over its nuclear program. President Trump withdrew from the 2015 agreement in May 2018 and reinstated sanctions to limit Iranian oil sales, raising tensions with countries in Europe and Asia that have become reliant on Iran for energy.

The Treasury Department placed sanctions on 26 individuals and “entities” affiliated with the Islamic Revolutionary Guards Corps Quds Force, which the United States said has shipped approximately $500 million worth of Iranian oil in the last year. The sanctions freeze any assets held in the United States of those affiliated with the shipping network and prohibit them from doing business with Americans. The action also identifies 11 ships, placing anyone who owns or operates them on a Treasury list and exposing any port that lets them in, or firms that fuel or offload them, to future sanctions.

The shipping network is run by Rostam Ghasemi, Iran’s former minister of petroleum, and the United States said it has been used to facilitate the flow of money to Hezbollah and the government of President Bashar al-Assad of Syria. The United States considers Hezbollah a terrorist organization even though members of the group have embedded into legitimate parts of the Lebanese government.

“Iran continues to take provocative actions to destabilize the region and the world,” Treasury Secretary Steven Mnuchin said in a statement. “Our actions over the last two weeks should serve as a strong warning to anyone considering facilitating the Quds Force’s oil sales that there will be swift consequences.”

As the United States stepped up sanctions pressure, Iran seemed to be pursuing a maximum-pressure strategy of its own.

After a series of seemingly conflicting announcements, President Hassan Rouhani said on Wednesday that he would announce new actions that would violate the terms of the nuclear deal, making it clear that Iran was trying to press Europe to make good on its promises to neuter American-led sanctions by compensating Tehran for lost oil sales.

He offered no details, other than to say the next move to step away from the accord would have an “extraordinary” effect on Iran’s nuclear program.

The announcement by the Trump administration came days after it imposed sanctions against Iran’s space program and against an Iranian oil tanker that had been detained in Gibraltar for weeks on suspicion of violating European Union sanctions by trying to transport oil to Syria. Earlier this summer, the United States imposed sanctions on Hezbollah officials that it accused of helping Iran.

Senior administration officials said on Wednesday that the recent actions against Iran were meant to send a message to countries around the world that they can do business with either Iran or the United States.

The Trump administration has been at odds with the European Union since abandoning the nuclear agreement. It has also warned China, which has continued to import Iranian oil, and in July imposed economic penalties on a Chinese company flouting American sanctions.

Underscoring the lengths that the Trump administration is willing to go to, the United States is for the first time using a counterterrorism rewards program to disrupt an arm of a foreign government.

Speaking to reporters at the White House on Wednesday, Mr. Trump said he believed that Iran wanted to make a deal with the United States, and he offered an assurance that he was not seeking regime change in Iran.

“They have tremendous potential, and I think they’re going to want to take advantage of that,” Mr. Trump said, according to a pool report.

Mr. Trump left open the possibility that he could meet with Mr. Rouhani of Iran at the United Nations General Assembly gathering in New York this month.

“Anything is possible,” he said.

Brian Hook, the State Department’s special envoy for Iran issues, said on Wednesday that the United States was prepared to pay up to $15 million to any person who offered information about the financial network run by the Islamic Revolutionary Guards Corps and its shadowy Quds Force. The money would be paid from the department’s Rewards for Justice program, which has spent more than $150 million since 1984 to track and stop terrorist activity across the world.

The Trump administration in April designated the Revolutionary Guards a foreign terrorist organization to hamper its support of Shiite militias elsewhere in the Middle East, and over concerns raised by some national security officials that Tehran would retaliate against American troops in the region.

“We have taken this step because the I.R.G.C. operates more like a terrorist organization than it does a government,” Mr. Hook told reporters at the State Department. He said the military unit was training, funding and equipping proxy militias, including Hezbollah in Syria as well as Hamas.

“Iran wants these groups to extend the borders of the regime’s revolution and sow chaos and sectarian violence,” Mr. Hook said.

Still, Mr. Hook insisted that Mr. Trump remained open to negotiations with Iran’s leaders, but added, “Iran never comes back to the negotiating table without diplomatic isolation, economic pressure or the threat of military force.”

“We think that this creates the right atmosphere that will lead, eventually, to talks,” Mr. Hook said. “But that’s a decision that the Iranians have to make.”

He refused to discuss a tentative proposal by President Emmanuel Macron of France to offer Iran a $15 billion bailout to keep it from violating the terms of the nuclear accord. Iran has threatened to raise its nuclear enrichment level to 20 percent, an announcement that could come as soon as this week, in the third direct but easily reversible violation of the deal.

“There is no proposal,” Mr. Hook said, noting that the offer by Mr. Macron had not been formally put forward, “and so we are not going to comment on something that doesn’t exist.”

Mr. Rouhani has adhered to his previously announced schedule of taking further steps away from the agreement every 60 days; the next deadline is Friday. But at the same time, he said he would continue to negotiate with European nations for another two months, a period that seemed intended to allow for some kind of negotiation, direct or indirect, with Washington.

One possible next step for Mr. Rouhani would be to announce that Iran is increasing the level to which it is enriching uranium. The agreement allows for enrichment to 3.67 percent, which is suitable for fuel for nuclear power plants, but not nuclear weapons. Iran has already exceeded that limit, inspectors from the International Atomic Energy Agency have confirmed, but only by a small margin. But based on statements by Iranian lawmakers, European officials expect Iran to announce that it is producing fuel at 20 percent enrichment, to supply a small reactor that produces medical isotopes in Tehran.

The 20 percent enrichment would be a concern because it is a relatively short leap to produce bomb-grade fuel. Iran says it has no intention of doing so. But the core of the 2015 agreement was to assure that it would take Iran more than a year to produce a bomb’s worth of weapons-grade material. Any prolonged move to 20 percent enrichment would shorten that timeline to under a year.

Iran may also install new centrifuges that enrich uranium at a far faster rate than the old models that were dismantled in 2015 and 2016. That, too, would speed the country’s ability to “break out” and produce bomb material.

Mr. Rouhani has often noted that each of these steps is easily reversible, if Iran gets the sanctions relief it demands. Mr. Hook called that “nuclear extortion” at the State Department; the Iranians say it is simply the mirror image of the American pressure campaign.